Optical properties of mesogen-coated gold nanoparticles
In this work, the physical and optical properties of gold nanoparticles functionalized with laterally grafted nematic ligands were studied. In particular, the influence of the nanoparticle size on the mesomorphic behavior and optical properties of the composite was investigated. To obtain an in-plane alignment of the mesogens, thin oriented films were prepared by shearing and characterized by polarized absorption spectroscopy. While the sub-2nm nanoparticle thin film only showed birefringence due to a strong damping of the plasmon resonance, larger NPs exhibit a strong dichroism with a shift of the NP plasmon resonance by about 50 nm. These results demonstrate the possibility to obtain a bulk NP metamaterial with tunable plasmonic properties by chemical engineering of the NP ligands.